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https://www.readbyqxmd.com/read/28926221/fourier-transform-ms-and-closed-path-multi-reflection-time-of-flight-ms-using-an-electrostatic-linear-ion-trap
#1
Eric T Dziekonski, Joshua T Johnson, Kenneth W Lee, Scott A McLuckey
An electrostatic linear ion trap (ELIT) has been configured to allow for the simultaneous acquisition of mass spectra via Fourier transform (FT) techniques (frequency measurement) and via time-of-flight (TOF) (time measurement). In the former case, the time-domain image charge derived from a pick-up electrode in the field-free region of the ELIT is converted to frequency-domain data via Fourier transformation (i.e., FT-ELIT MS). In the latter case, the time difference between ion injection into the ELIT and ion detection after release from the ELIT using a micro-channel plate (MCP) enables the acquisition of multi-reflection time-of-flight mass spectra (MR-TOF MS)...
September 19, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28890673/navigating-freely-available-software-tools-for-metabolomics-analysis
#2
REVIEW
Rachel Spicer, Reza M Salek, Pablo Moreno, Daniel Cañueto, Christoph Steinbeck
INTRODUCTION: The field of metabolomics has expanded greatly over the past two decades, both as an experimental science with applications in many areas, as well as in regards to data standards and bioinformatics software tools. The diversity of experimental designs and instrumental technologies used for metabolomics has led to the need for distinct data analysis methods and the development of many software tools. OBJECTIVES: To compile a comprehensive list of the most widely used freely available software and tools that are used primarily in metabolomics...
2017: Metabolomics: Official Journal of the Metabolomic Society
https://www.readbyqxmd.com/read/28862997/a-novel-optically-transparent-rf-shielding-for-fully-integrated-pet-mri-systems
#3
C Parl, A Kolb, A M Schmid, H F Wehrl, J A Disselhorst, P D Soubiran, D Stricker-Shaver, B J Pichler
Preclinical imaging benefits from simultaneous acquisition of high-resolution anatomical and molecular data. Additionally, PET/MRI systems can provide functional PET and functional MRI data. To optimize PET sensitivity, we propose a system design that fully integrates the MRI coil into the PET system. This allows positioning the scintillators near the object but requires an optimized design of the MRI coil and PET detector. It further requires a new approach in realizing the radiofrequency (RF) shielding. Thus, we propose the use of an optically transparent RF shielding material between the PET scintillator and the light sensor, suppressing the interference between both systems...
September 1, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28843027/lc-ms-smrm-method-development-and-validation-of-different-classes-of-pain-panel-drugs-and-analysis-of-clinical-urine-samples
#4
M Athar Masood, Timothy D Veenstra
Urine Drug Testing (UDT) is an important analytical/bio-analytical technique that has inevitably become an integral and vital part of a testing program for diagnostic purposes. This manuscript presents a tailor-made LC-MS/MS quantitative assay method development and validation for a custom group of 33 pain panel drugs and their metabolites belonging to different classes (opiates, opioids, benzodiazepines, illicit, amphetamines, etc.) that are prescribed in pain management and depressant therapies. The LC-MS/MS method incorporates two experiments to enhance the sensitivity of the assay and has a run time of about 7 min...
August 26, 2017: Basic & Clinical Pharmacology & Toxicology
https://www.readbyqxmd.com/read/28833398/assessment-of-time-to-glucose-peak-during-an-oral-glucose-tolerance-test
#5
LETTER
Adam Hulman, Daniel R Witte, Dorte Vistisen, Kristine Faerch
No abstract text is available yet for this article.
August 21, 2017: Clinical Endocrinology
https://www.readbyqxmd.com/read/28830233/investigating-and-analyzing-three-cohorts-of-mushroom-poisoning-caused-by-amanita-exitialis-in-yunnan-china
#6
J Sun, H-J Li, H-S Zhang, Y-Z Zhang, J-W Xie, P-B Ma, C Guo, C Y Sun
Amanita exitialis is a lethal mushroom found in China. Knowledge regarding taxonomic characterization, toxin detection, general poisoning conditions, clinical manifestations, laboratory examinations, and clinical treatments for this species is currently lacking. We investigated three A. exitialis mushroom poisoning cohorts in Yunnan Province in 2014 and 2015, involving 10 patients. Mushroom samples were identified by morphological and molecular studies. Ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry was used to detect the peptide toxins in the mushroom samples...
January 1, 2017: Human & Experimental Toxicology
https://www.readbyqxmd.com/read/28783153/pecan-library-free-peptide-detection-for-data-independent-acquisition-tandem-mass-spectrometry-data
#7
Ying S Ting, Jarrett D Egertson, James G Bollinger, Brian C Searle, Samuel H Payne, William Stafford Noble, Michael J MacCoss
Data-independent acquisition (DIA) is an emerging mass spectrometry (MS)-based technique for unbiased and reproducible measurement of protein mixtures. DIA tandem mass spectrometry spectra are often highly multiplexed, containing product ions from multiple cofragmenting precursors. Detecting peptides directly from DIA data is therefore challenging; most DIA data analyses require spectral libraries. Here we present PECAN (http://pecan.maccosslab.org), a library-free, peptide-centric tool that robustly and accurately detects peptides directly from DIA data...
September 2017: Nature Methods
https://www.readbyqxmd.com/read/28783002/non-targeted-workflow-for-identification-of-antimicrobial-compounds-in-animal-feed-using-bioassay-directed-screening-in-combination-with-liquid-chromatography-high-resolution-mass-spectrometry
#8
Robin S Wegh, Bjorn J A Berendsen, Wilma D M Driessen-Van Lankveld, Mariël G Pikkemaat, Tina Zuidema, Leen A Van Ginkel
A non-targeted workflow is reported for the isolation and identification of antimicrobial active compounds using bioassay-directed screening and LC coupled to high-resolution MS. Suspect samples are extracted using a generic protocol and fractionated using two different LC conditions (A and B). The behaviour of the bioactive compound under these different conditions yields information about the physicochemical properties of the compound and introduces variations in co-eluting compounds in the fractions, which is essential for peak picking and identification...
August 22, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28753686/understanding-individual-differences-in-color-appearance-of-thedress-based-on-the-optimal-color-hypothesis
#9
Keiji Uchikawa, Takuma Morimoto, Tomohisa Matsumoto
We performed a theoretical analysis based on our optimal color hypothesis to explain why "#TheDress" image had a different color appearance for different observers (observer-dependent perception). We then carried out an experiment to test the hypothesis derived from the aforementioned theoretical analysis. In the optimal color hypothesis, the visual system picks the optimal color distribution that provides the best fit to the luminance distribution at a scene. The peak of the best-fit optimal color distribution corresponds with the illuminant's color temperature...
July 1, 2017: Journal of Vision
https://www.readbyqxmd.com/read/28752757/detailed-investigation-and-comparison-of-the-xcms-and-mzmine-2-chromatogram-construction-and-chromatographic-peak-detection-methods-for-preprocessing-mass-spectrometry-metabolomics-data
#10
Owen D Myers, Susan J Sumner, Shuzhao Li, Stephen Barnes, Xiuxia Du
XCMS and MZmine 2 are two widely used software packages for preprocessing untargeted LC/MS metabolomics data. Both construct extracted ion chromatograms (EICs) and detect peaks from the EICs, the first two steps in the data preprocessing workflow. While both packages have performed admirably in peak picking, they also detect a problematic number of false positive EIC peaks and can also fail to detect real EIC peaks. The former and latter translate downstream into spurious and missing compounds and present significant limitations with most existing software packages that preprocess untargeted mass spectrometry metabolomics data...
September 5, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28703318/ft-artifacts-and-power-function-resolution-filter-in-fourier-transform-mass-spectrometry
#11
Basem Kanawati, Theresa Bader, Karl-Peter Wanczek, Yan Li, Philippe Schmitt-Kopplin
RATIONALE: Peak picking algorithms in mass spectrometry face the challenge of picking the correct signals from a mass spectrum. In some cases signal wiggles (side lobes) are also chosen in the produced mass list as if they were real signals. Constraints which are defined in such algorithms do not always guarantee wiggle free accurate mass list generation out of raw mass spectra. This problem intensifies with acquisitions, which are accompanied with longer transients. Thus, the problem represents a contemporary issue, which propagates with modern high memory digitizers and exists in both MS and MS/MS spectra...
July 13, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28622319/flicker-electroretinograms-recorded-with-mydriasis-free-reteval-system-before-and-after-cataract-surgery
#12
G Miura, E Sato, S Yamamoto
PurposeThe purpose of this study is to compare the amplitudes and peak times of the flicker electroretinograms (ERGs) recorded before and after cataract surgery with the RETeval system (LKC Technologies, Gaithersburg, MD, USA) from eyes without dilation.Patients and methodsThirty-two eyes of 32 patients (77.3±6.5 years) that had grade 2 Emery-Little nuclear or cortical cataract without any other abnormalities were studied. Flicker ERGs were recorded with the RETeval system under mydriatic-free conditions. Skin electrodes were used to pick-up the ERGs that were elicited by white light delivered at a rate of 28...
June 16, 2017: Eye
https://www.readbyqxmd.com/read/28542374/targeted-box-and-blocks-test-normative-data-and-comparison-to-standard-tests
#13
Kimberly Kontson, Ian Marcus, Barbara Myklebust, Eugene Civillico
BACKGROUND: The Box and Block Test (BBT) is a functional outcome measure that is commonly used across multiple clinical populations due to its benefits of ease and speed of implementation; reliable, objective measurement; and repetition of motion. In this study, we introduce a novel outcome measure called the targeted BBT that allows for the study of initiation, grasping, and transport of objects, and also of object release. These modifications to the existing test may increase the ecological validity of the measure while still retaining the previously stated benefits of the standard BBT...
2017: PloS One
https://www.readbyqxmd.com/read/28520864/from-chromatogram-to-analyte-to-metabolite-how-to-pick-horses-for-courses-from-the-massive-web-resources-for-mass-spectral-plant-metabolomics
#14
Leonardo Perez de Souza, Thomas Naake, Takayuki Tohge, Alisdair R Fernie
The grand challenge currently facing metabolomics is the expansion of the coverage of the metabolome from a minor percentage of the metabolic complement of the cell towards the level of coverage afforded by other post-genomic technologies such as transcriptomics and proteomics. In plants this problem is exacerbated by the sheer diversity of chemicals that constitute the metabolome with the number of metabolites in the plant kingdom generally being considered to be in excess of 200 000. In this review we focus on web-resources that can be exploited in order to improve analyte and ultimately metabolite identification and quantification...
May 17, 2017: GigaScience
https://www.readbyqxmd.com/read/28505421/development-of-high-performance-chemical-isotope-labeling-lc-ms-for-profiling-the-carbonyl-submetabolome
#15
Shuang Zhao, Margot Dawe, Kevin Guo, Liang Li
Metabolites containing a carbonyl group represent several important classes of molecules including various forms of ketones and aldehydes such as steroids and sugars. We report a high-performance chemical isotope labeling (CIL) LC-MS method for profiling the carbonyl submetabolome with high coverage and high accuracy and precision of relative quantification. This method is based on the use of dansylhydrazine (DnsHz) labeling of carbonyl metabolites to change their chemical and physical properties to such an extent that the labeled metabolites can be efficiently separated by reversed phase LC and ionized by electrospray ionization MS...
May 25, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28449877/two-stage-algorithm-vs-commonly-used-approaches-for-the-suspect-screening-of-complex-environmental-samples-analyzed-via-liquid-chromatography-high-resolution-time-of-flight-mass-spectroscopy-a-test-study
#16
Saer Samanipour, Jose A Baz-Lomba, Nikiforos A Alygizakis, Malcolm J Reid, Nikolaos S Thomaidis, Kevin V Thomas
LC-HR-QTOF-MS recently has become a commonly used approach for the analysis of complex samples. However, identification of small organic molecules in complex samples with the highest level of confidence is a challenging task. Here we report on the implementation of a two stage algorithm for LC-HR-QTOF-MS datasets. We compared the performances of the two stage algorithm, implemented via NIVA_MZ_Analyzer™, with two commonly used approaches (i.e. feature detection and XIC peak picking, implemented via UNIFI by Waters and TASQ by Bruker, respectively) for the suspect analysis of four influent wastewater samples...
April 20, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28438305/cardiovascular-response-to-recreational-hockey-in-middle-aged-men
#17
Zack A Goodman, Scott G Thomas, Robert C Wald, Jack M Goodman
The present study examined the hemodynamic response to recreational pick-up hockey relative to maximal exercise testing in middle-aged men. A total of 23 men with a mean age of 53 ± 7 years were studied. Graded exercise testing on a cycle ergometer determined maximal oxygen consumption, blood pressure (BP), and heart rate (HR). Ambulatory BP and Holter electrocardiographic monitoring was performed during one of their weekly hockey games (mean duration = 45 ± 7.2 minutes): for "On-Ice" responses (PLAY; data recorded while standing immediately after a shift; 8...
June 15, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/28371585/validity-of-field-assessments-to-predict-peak-muscle-power-in-preschoolers
#18
Sara King-Dowling, Nicole A Proudfoot, John Cairney, Brian W Timmons
Field-based fitness assessments are time- and cost-efficient. However, no studies to date have reported the predictive value of field-based musculoskeletal fitness assessments in preschoolers. The purpose of this study was to determine the validity of 2 field assessments to predict peak muscle power in preschool-aged children. Four-hundred and nineteen 3- to 5-year olds participated (208 girls, 211 boys; mean age: 4.5 ± 0.9 years). Peak power (PP) was evaluated using a modified 10-s Wingate protocol as the criterion standard...
April 3, 2017: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
https://www.readbyqxmd.com/read/28355412/influence-of-work-pace-on-upper-extremity-kinematics-and-muscle-activity-in-a-short-cycle-repetitive-pick-and-place-task
#19
Tessy Luger, Svend Erik Mathiassen, Divya Srinivasan, Tim Bosch
Objectives: This study investigated the extent to which controlled changes in work pace in a cyclic pick-and-place task influence upper extremity kinematics and muscle activity, and whether an effect depends on working height. Methods: Thirteen participants performed the task for 4 min at each of five work paces ranging from 8 to 12 cycles·min-1 in each of two experimental conditions where the hand was moved horizontally with an average upper arm elevation of 30° and 50°, respectively...
April 1, 2017: Annals of Work Exposures and Health
https://www.readbyqxmd.com/read/28353646/intraguild-predation-dynamics-in-a-lake-ecosystem-based-on-a-coupled-hydrodynamic-ecological-model-the-example-of-lake-kinneret-israel
#20
Vardit Makler-Pick, Matthew R Hipsey, Tamar Zohary, Yohay Carmel, Gideon Gal
The food web of Lake Kinneret contains intraguild predation (IGP). Predatory invertebrates and planktivorous fish both feed on herbivorous zooplankton, while the planktivorous fish also feed on the predatory invertebrates. In this study, a complex mechanistic hydrodynamic-ecological model, coupled to a bioenergetics-based fish population model (DYCD-FISH), was employed with the aim of revealing IGP dynamics. The results indicate that the predation pressure of predatory zooplankton on herbivorous zooplankton varies widely, depending on the season...
March 29, 2017: Biology
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